Antiaircraft fire-control apparatus



Dec. 92 1924. I 1,519,015

A. BARR ET AL ANTIAIRCRAFT FIRE CONTROL APPARATUS MMM 15M,

Patented Dec. 9, 1924.

umn-:D STATES 1,519,015 PATENTV- oFFicE.

ARCHIBALD BARR AND WILLIAM STROUD, OF ANNESLAND, GLASGOW, SCOTLAND, ASSIGNORS TO BARR AND STROUD, LIMITED, F 'GLASGOL SCOTLAND.

ANTIAIRCRAFT FIRE-CONTROL APPARATUS.

Application filed December 26, 1922. Serial'No. 609,028.

This invention relates to improved api-l paratus for use in obtaining the requisite data for anti-aircraft gunnery.

Apparatus according to this invention' comprises, (1) sighting apparatus; (2) an element to be set in accordance with the known height of the target at the instant of observation operating to control the Yangle ofv sight of the sighting apparatus; (3) a variable speed drive controlling the position of (2) to keep the sighting apparatus directed on the target for angle of sight, and

give the value of the horizontal range and lv (velocity of a proach along the horizontal range and in t e vertical plane containinw target and observer on a selected scale) (4) a device (say a multiple camper equivalent) one variable of which (say rotation) is set according to the height of the target, while the second variable (saytranslation) is 'set by (3)- according to the horizontal range of the target, the device being so constructed as to produce motion according to T (time,

of Hight); (5) means for multiplying the speed given by (3) by T so as to give the product lv T; (6) means for setting (4) by an amount v T given by (5), associatedwith mechanism for giving or exhibiting the quadrant or tangent elevation and the fuse number, this mech nism being rotatable, say, in accordance with the height of the target and movable with the device (4) in` accordance with the horizontal range of the target; (7) a variable speed drive controlling the azimuthal positio'n of the sighting apparatus and thereby giving (angular velocity); and (8) means for multiplyin by T given by (4) so as to give or exhi it the product :o T.

In the description which follows it will be assumedt-hat the aircraft is moving in a straight line with uniform speed at a constant heightH and that the observing station is near thel gun.

In the first instance the invention will be described as applied to the case of indirect gun fire onland and the,problem will be considered under two headings: (1) motion in the vertical plane containing the observing station, and (2) motion at right angles thereto.

In case (l) the aircraft will be assumed to be ilying at a constant speed V at a constant height H1 in the verti cal plane containing the observing stat-ion. I-I is measured by a. Suitable height finder. With the height known, the speed V may be determined after aknown manner.

Given H and V, the quadrant elevation Q E of the gun andA the required fuse set t-ing F can be calculated by reference to a chart embodying the requisite data for the firing of the gun. By this Vinvention the required values of Q, E and F for the predicted positionl of the aircraft, are obtained by nechanism continuously and instantaneous y.

An exam le of construction according to this inventlon will now be described with reference to the accompanying drawing, in which:-\ I f v 'Figure 1 is a sectional elevation and Figure 2 is a broken pllan partly in "section of an instrument, eac partly diagrammatic.

The known height H is set off by rotating handle 1 with reference to a fixed scale (not shown). A time-of-fiight multiple cam 2 is fixed to the shaft of 1 to which 1s also fixed toothed wheel 3 gearing with toothed wheels 4, 5 and 6 fixed to their respective shafts. Multiple cam 7 is fixed to the shaft of 5` and multiple cam 8 is fixed to the shaft ofr 4. A long pinion rod 9 ixed lto the shaft of 6. Gearing with 9 is a rack 10 (suitably guided) carrying a pin 11 engaging in a slot of an arm 13 rigidly fixed to rod 14 carrying telescopes 15 and 16, one at each end. Thus as the height is set oit' by turning handle 1 the multiple cams 2-,for time of Hight- 7-for quadrant elevation-and 8-for fuse indication-are all simultaneously rotated While the pin 11 is raised or lowered, thus increasing or decreasing the angle of sight of 15 and 16. 20 is a long screw, carrying nut 21 to which is fixed a transverse bar 22 supporting guides yfor the rack 10 and guides for three plungers 25, 26, 27 resting on multiple calns 2, 7, 8, respectively.

A handle 30, see Figure 2, is provided for initially settin the position of nut 21 by the rotation o screw 2O so that the angle of sight of the two telescopes 15, 16 may loo llO

h 31 gearing With'wheel 32 fixed to one element 33 of a differential gear 33, 34, 35. The spindle of jockey elelnent 34 is fixed to screw 20, and bevel 35 is fixed to a bevel 36 gearing with a bevel 37 which can be driven mechanically in either direction at an adjustable rate. Thus the observer at 15 adjusts handle 30'to suit the. initial angle vof sight of the target and then adjusts the rate continues to correspond to that of the target. Meantime the observer, say, at telescope 16 is provided yWith similar means for the initial set-tin of the azimuthal position of the case an with an adjustable drive for maintaining that position. The initial setting is done by means of handle- 40, the parts 40 47 corresponding to the parts 30 37 already discussed. In this case the variable drivev comes from 47 and the -spindle of jockey 44 vis fixed to shaft 50 whose bearings are fixed to the case 5-1. Pinion wheels 52 and 53 are fixed to shaft 50, pinion 52 gearing with a large toothed Wheel .54. carrying dial 56, While pinion 53 gears With a large toothed Wheel 55 fixed relatively to the. ground; the number of teethoftlie 7 various Wheels 54 and. 55 and associated pinions 52 and 53 being such that dial 56 remains fixed relatively to Wheel 55 and therefore relatively to the ground.

The variable drives shown are of well known type and are not Vdescribed in detail. Handle (situated conveniently for the observer at telescope 15) is operated so as to furnish the value of o, i. e., the velocity of approach along the horizontal range and in the vertical planecontaining target and observer u on the selected scale, while han-l dle 61 situated conveniently for the observer at telescope 16) is operated'so as to furnish the value of the angular velocity o.

Thus at the commencement of operations the observer at telescope 16 adjusts the handle 40 for initial azil'nuthal position: meantime the observer at 15 adjustshandle 30 for initial angle of ,sight when the telescopes Will be directed on the target. By adjustments'of the variable drive handles 61 for azimuthal angular velocity and 60 for linear velocity of approach, the telescopes should keep on the target at all events for a short time'.

The velocities o and v require to bc multiplied by T, the time of flight. Multiple cam 2 is constructed to give the yvalue of the time of flight. Therefore, if I2 is rotated for the 'known height while the plunger 25 with a sloping rack gearing into a spiral pinion to which is -fixed pinion 7 gearing Wlth a rack 72 carrying a pin 73 engaglng in\ a slotted arm 74 which has a fulcrum at j -Handle 60 whichsets ofi' the variable drive for /v by means of screw carries a nut 81 supporting a rack 82 vto Which is fixed a pin j 83 Working in a slot in an arm 84, Figure 1, of rotation of 37 so that the angle of sight,r

83 from its zero position is a measure of r.

The rotation of pinion rod 85 is communicated to toothed Wheel 86 and screw 87 (both rigidly fixed H,to 85). .VVheel 86 gears with wheel 88 fixed to left-handed screw 89. The gearing is such that the two screws 87 and 89. (if of equal pitch) rotate equally in opposite directions. Platform 90 carrying the lthree multiple cams is translated by the rotation of screws 87 and 89 through a distance u T with reference tothe plungers 25. 26 and 27. These plungers will therefore now rest upon portions of the multiple cams corresponding to the predicted position of the target., Plunger 26 gearing with'spral pinion to which is fixed pointer 96 can 1n this way be arranged to indicate thcv quadrant elevation u on a fixed circular scale (not shown) -while plunger 27 gearing With spiral pinion A97 carrying pointer 98 AWards and this motion is communicated by gear, 53, engaging with 55, which is fixed, and drlves the frame 51 carrying the mechanism which is mounted to turn asimuthallyl.'-

The product o T isobtained in a, Similar fashion. Thus, when motion yin accordance with the value of o is Iset off by handle'61y thereby turning screw 102 which translates nut 101 carrying rack 103 provided with pin 104 which engages inthe slotted arm 74. and as rack 103 'gears with long pinion 'rod 105, the motion of 105 is a measure of o T.

' erence tothe ground so that and 54 may be removed, a fixed scale belng This motion is communicated by bevel wheels to the pointer 106.

In the case lof direct gun fire the Q, E cam 7 can be replaced by a cam arranged to glve tangent elevations (T E). The angu lar correction f'or deflection about a vertical axis will still be as-before T `as given by the deflection of the pointer 106 with refcrence to 51. In this case there' will be no necessity to provide a dial 56 fixed with rei:-

the parts attached to the case so that the deflection may be read by the pointer 106 upon this scale.

For use on board ship, it is necessary that the axis of the apparatus shall be maintained vertical and further that a diametral linel upon the upper flat circular face of 51 shall be maintained in a fixed direction in space.

We claim 1. Apparatus comprising 1) sighting apparatus, (2) an element to be set in accordance with the known height of the targetat the instant of observation operating to control the angle of Sight of the sighting apparatus; (3) a variable speed drive controllingthe position of (2) to keep the sighting apparatus directed on the target for angle of sight and give the value of the horizontal range and 'v (velocity of approach along the horizontal range and in the vertical plane containing target and observer on a selected scale); (4) a device having one variable capable of being set according to the height of the target, and a second variable capable of being set by (3) according to the horizontal range of the target, the device being so constructed as to produce motion according to T (time of flight) 5) means for multiplying the speed given by (3) by T so as to give the product yof? lv T; (6) means for setting (4) by an amount 'v T given by (5), associated with mechanism for giving the quadrant or tangent. elevation and the fusenumber, this mechanism being movable, in accordance with the height of the target and movable with the devlce (4) in accordance with the horizontal range of the target; (7 a variable speed drive controlling the azimuthal position of the sighting apparatus thereby giving e (angular velocity) and (8) means for multiplying by T given by (4) so as to give or exhibit the product e) T.

2. Apparatus comprising (1) sighting apparatus, (2) an element to be set 1n `accordance with the known-height of the target at the instant of observation operating to control the angle of sight of the sighting apparatus; (3) a variable speed drive controlling the position of (2) to keep the sighting apparatus directed on the target for angle of sight, and give the 'value of the horizontal range and fv (velocity of approach along the horizontal range and in the vertical plane containing target and observer on a selected scale); (4) a multiple cam capable of being set rotationally according to the height of the target, and of bein set by translation by (3) according to the orizontal range of the target, the dcvice being so constructed as to produce mo` tion according to T (time of flight); (5) means for multiplying the speed given by (3) by T so as to give the product of 'u T; (6) means for setting (4) by an amount o T given by (5), associated with mechanism for giving the quadrant or tangent elevation and the fuse number` this mechanism bein movable in accordance with thc height of tie target and movable with the device (4) in accordance with the horizontal range of thel target; (7) a variable speed drive controlling the azimuthal position of the sighting apparatus thereby giving o (angular velocity); and (8) means for multiplying ci by T given by (4) so as to give or exhibit the product T. l

3. Apparatus comprising (1) sighting apparatus, (2) an element to be set 1n accordance with the known height of the target at the instant of observation operating to control the angle of sight of the sighting apparatus; (3) a variable speed drive controlling the position of (2) to keep the sighting apparatus directed on the target for angle of sight, and give the value of the horizontal ran e and 'v (velocity of approach along tie horizontal range and in the vertical plane containing target and observer on a selected scale); (4) a multiple cam having one variable capable of being set according to the height of the target, and a second variable capable of being set by (3) according to the horizontal range of the target, the device being so constructed as to produce motion according to T (time of flight); (5) means for multiplying the speed given by (3) by T so as to give the product of o T; (6) means for setting (4) by an amount v T given by (5), associated with two additional multiple cams for giving the quadrant or tangent elevation and the fuse number. these cams being `variable in accordance with the height of the target: and variable with the second variable of device (4) in accordance withthe horizontal range of the target; (7) a variable speed drive controlling the azimuthal position of the sighting apparatus' thereby giving (angular velocity); and (8) means for multiplying o) by T given by (4) so as to give or exhibit the product@ T.

4. Apparatus comprising (l) sighting ap paratus, (2) an element to be set 1n accordance with the known height of the target at the instant of observation o erating to control the angle of sight of t e sighting aplili) paratus; (3) Aa variable speed drive conb'y anamount v T given by (5), associated trolling the position of (2) to keep the sightwith v.two additional multiple cams for giving apparatus directed on the target for angle 'ingthe quadrant or tangent elevation and of sight, and give the value vof the horizontal the"v fuse number, these'cams being rotatable range and 'v (velocity of approach along tlhe in accordance with the hei ht of the target horizontalrange and in the vertical lane and translatable withthe evice (4) in ac-y containing target and observer on a se ected cor-dance with the .horizontal range of the scale); (4) amultiple cam capable of betarget; (7) a variable speed drive controling set rotationally according to the height ling the azimuthal position of the sighting of the target, and of being set. by translation apparatus thereby giving c) (angular velocby (3) laccording to the horizontal range of ity); and (8) means for multiplying (o by the target, the device being so constructed 'l given by (4) so as to give or exhibit; the

, as to produce motion according to T (time product en T.

of ight); (5) means for multiplying the speed given by (3) by T so as to give the ,p ARCHIBALD BARR. product of v T; (6) means for setting (4) WILLIAM STROUD. 

